1. Field of the Invention
The present invention relates to spin-on filter assemblies for filtering fluids, such as, for example, oil, fuel, or coolant.
More particularly, the present invention relates to a method of applying a grippable slip-resistant coating to a selected portion of a spin-on filter, using a fluidized bed coating apparatus, and to a spin-on filter which is a product of the described process.
2. Description of the Background Art
Spin-on fluid filters, generally, are well known and in wide use for filtering oil on internal combustion engines, for filtering gasoline at gasoline pumping stations, for filtering fuel oil or diesel fuel, as well as for other applications. These filter assemblies are generally cylindrical, often with a circular base plate, having an internally threaded central mounting hole formed therein, to allow spin-on installation thereof.
In many applications, particularly in crowded engine compartments on vehicles, an operator may have difficulty generating enough torque, by hand gripping, to install a spin-on filter to the manufacturer's torque specification. This may be due to other components blocking access to the filter mounting area, to oil spillage on to the filter housing exterior surface, or to other factors. Sometimes a tool, such as a filter wrench or the like, may be used to help gain added torque, but the tool may also be difficult to fit into the space provided. In addition, using a filter wrench to install a filter may even damage the filter housing, possibly leading to leakage of the filter, and is disfavored.
Some applications are known, generally, for applying slip-resistant surface treatments to enhance grippability of a surface. Slip-resistant enhanced gripping materials are known for use on stair steps, on selected areas of boat decks, and on some lawn furniture. However, it believed that heretofore, a method has not been available to place a slip-resistant coating on a grippable surface of a spin-on filter housing, using a fluidized bed coating apparatus, to provide a slip-resistant enhanced gripping surface.
A need still exists in the art for a method of manufacturing an improved spin-on filter having a slip-resistant coating thereon with a textured surface to make it easier to grab and tighten.